In recent years, the agricultural sector worldwide has been called upon to make efforts to reduce greenhouse gases, with particular attention being given to reducing methane emissions from rice paddies. The RiceGX-SATREPS project will develop and implement a large paddy area water management method to reduce methane emissions without reducing rice yields, as well as a method to monitor and evaluate GHG reductions, targeting rice paddies in Pursat Province, Cambodia, where irrigation facilities have been reintroduced through the Japanese ODA loan project.

Theme 1．Building a “Water Management System for Methane Emission Reduction” and upgrading intermittent irrigation.

Based on an understanding of the hydrological environment affected by climate change, we aim to build a water management system (irrigation system + drainage system) that uses information and communication technology (ICT) to enable intermittent irrigation of a large paddy area. In addition, to implement intermittent irrigation, we will develop tools that will enable information sharing between irrigation and drainage facility managers, farmers, and other stakeholders and will support decision-making. The results will be compiled into manuals and guidelines.

Activities
1.1 Project future water resource situation under climate change
1.2 Develop an ICT-based irrigation and drainage system for large paddy area
1.3 Develop a manually operating irrigation system for large paddy area
1.4 Develop an ICT decision support application software for farmers to appropriately implement the “Water Management System for Methane Emission Reduction”
1.5 Conduct training on the operation and management of "Water Management System for Methane Emission Reduction" and decision support application software

Theme 2. Development of an estimation method for methane emission reduction in a large paddy area using “Water Management System for Methane Emission Reduction”

This theme establishes a foundational monitoring method using a tower observatory (micrometeorological method) and attempts to develop a portable monitoring system using unmanned aerial vehicles to estimate methane emission and its reduction by intermittent irrigation in a large paddy area. Based on the results obtained, this theme publishes manuals and/or guidelines for the monitoring methods.

Activities
2.1 Establish a methane emission monitoring method using a tower observatory
2.2 Develop a methane emission monitoring method using a portable platform
2.3 Develop an estimation method for methane emission reduction based on the detection of plant drought stress and paddy water level using remote sensing
2.4 Develop a Measurement, Reporting and Verification (MRV) methodology suitable for large paddy area water management

Theme 3．Evaluation of the impact of implementation of intermittent irrigation on the environment and farm economy

We evaluate the impact on the environment of the target area and the economic impact of farm households by introducing a new technology, “Water Management System for Methane Emission Reduction”, through Life Cycle Assessment. In addition, we aim to create a project to generate carbon credits for the benefit of farmers by utilizing the MRV method developed in the project. Furthermore, with the goal of expanding the use of intermittent irrigation within Cambodia, we examine the potential for its dissemination through the classification and analysis of irrigated paddy areas.

Activities
3.1 Obtain and compile microdata for evaluating the “Water Management System for Methane Emission Reduction” into a database
3.2 Evaluate the “Water Management System for Methane Emission Reduction” through Life Cycle Assessment (LCA)
3.3 Classify irrigated paddy areas for dissemination of intermittent irrigation
3.4 Formulate a project to generate carbon credits using the Joint Crediting Mechanism (JCM) and its usage plan for farmers